programming - Tran Sang Dev Blog

programming

A collection of 3 posts

Get understand the user-agent string of the browser

Get understand the user-agent string of the browser

Let see an example of a user-agent string Mozilla/5.0 (Linux; Android 7.1.1; TONE-m17) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.89 Mobile Safari/537.36 This is a typical user-agent string whose content is combined of 4 parts * Mozilla/5.0 (Linux; Android

Promise based semaphore pattern in Javascript

Promise based semaphore pattern in Javascript

Let's start with a singleton pattern when you want to instantiate at most one instance of a class, or lazily initiate a value. let instance const getInstance = () => instance === undefined ? instance = initiateInstance()//this is a heavy task and should be done at most once in the whole life of the application

Best practices when working with universal time

Best practices when working with universal time

Wall clock and Timeline Let's divide Date's object methods into 2 categories: Wall clock type: * .getWallClockLabels() family: .getFullYear(), .getMonth(), .getDate(), .getHours(), .getMinutes(), .getSeconds(), .getMiliseconds(), .getDay(). * .setWallClockLabels() family: .setFullYear(), .setMonth(), .setDate(), .setHours(), .setMinutes(), .setSeconds(), .setMiliseconds(), .setDay(). * Wall clock constructor: new Date(year, month, date, hour, minutes, seconds, miliseconds) Timeline point